import time
import threading
def sing():
    while True:
        print("我在唱歌")
        time.sleep(1)
def dance():
    while True:
        print("我在跳舞")
        time.sleep(1)
sing_thread = threading.Thread(target=sing)
dance_thread = threading.Thread(target=dance)
sing_thread.start()
dance_thread.start()